제출 #564940

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
564940		Garguy22	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	745 ms	131072 KiB

tracks

#include <iostream>
#include <queue>
using namespace std;

typedef pair<int, int> pii;
#define mp make_pair
#define ff first
#define ss second

int n, m;
char grid[4007][4007];
int depth[4007][4007];
int dx[4] = {1, -1, 0, 0};
int dy[4] = {0, 0, 1, -1};

bool chk(int x, int y) {
	return (x > -1 && x < n && y > -1 && y < m && grid[x][y] != '.');
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	cin >> n >> m;
	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++)
			cin >> grid[i][j];
	}
	int ans = 1;
	deque<pii> q;
	q.push_back(mp(0, 0));
	depth[0][0] = 1;
	while(q.size()){
		pii u = q.front();
		q.pop_front();
		ans = max(ans, depth[u.ff][u.ss]);
		for(int i = 0; i < 4; i++){
			int x = u.ff + dx[i], y = u.ss + dy[i];
			if(chk(x, y) && depth[x][y] == 0){
				if(grid[x][y] == grid[u.ff][u.ss]){
					depth[x][y] = depth[u.ff][u.ss];
					q.push_front(mp(x, y));
				}else{
					depth[x][y] = depth[u.ff][u.ss] + 1;
					q.push_back(mp(x, y));
				}
			}
		}
	}
	cout << ans << endl;

	return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70